by Duncan Epping
A couple of weeks ago I received a cool PDF via email, this week it appeared online(source blog). Check it out:
The Source PDF:
VMware has collaborated with Cisco to produce a guide for deploying VMware Infrastucture 3 with Cisco switches. This guide covers the physical and virtual data network and storage network deployment considerations for ESX Server with suggested topologies and designs.
Just noticed the following topic, which definitely contains some good info about how ESX deals with memory. Thanks to Kit for clearing things up. These posts are valuable, keep ’em coming!
a short outtake:
Basically how aggressive do you want TPS to scan for shared pages? Obviously TPS has a cost to running in terms of CPU, but has benefits in terms of reduced memory usage. So there’s a tradeoff. We have a default that we think is a good balance, but we let the user modify that if they want.
Just dropped the following short script in a topic on the VMTN Community. It shuts down every VM on the host and than the host itself, but it will enter maintenance mode first, just to be sure that no other vm’s get migrated to this host.
VMLIST=’vmware-cmd -l’
for config in ${VMLIST}
do
vmware-cmd $config stop trysoft
done
vimsh -n -e /hostsvc/maintenance_mode_enter
shutdown -h now
addition: thanks forbes for the trysoft addition.
At a customer site we noticed that the ESX hosts were swapping, Nagios generated a nice alarm. After some research it seemed like certain VM’s were swapping to the VMFS volume, so not inside the OS but VMware swap usage. A closer look at the system revealed that we weren’t overcommitting. There was over 6GB of memory free and there were no limit’s set to the specific VM. Could it be just Nagios or… No, esxtop with the following commands “s2
The column swcur displays the current swap file usage, I marked the values higher than 0 red.
After a couple of searches it seemed that there is little info about swcur. But Kit Colbert, a VMware employee, posted on the vmtn forum about checking your current memory / swap usage in the file “/proc/vmware/sched/mem”. With cat you can easily display this, and with “watch -n 1” you can refresh your view every second. The following output was retrieved via the command “watch -n 1 cat /proc/vmware/sched/mem”:
We’ve migrated a VM which was swapping according to esxtop and nagios to another host, and as expected the swap remained. We powered down a VM that was swapping, and although the host had more than enough free mem available, the swap returned. It was less than before but still… The funny thing is that according to Kit it’s all about the column “swap out” and we did not see much action going on there.
I’m dazzled, anyone?
I just encountered the same bug that Aaron Delp blogged about in January:
It appears we have found a possible bug in the Deploy from Template Command in ESX 3.5. When you create a Windows Server based template and then try to deploy directly into an Active Directory with customization, the new system will get an error that a service failed to start when the machine is launched. This is because the VMWare BootRun service is not removing itself properly after deployment. This does not happen with deployments into a workgroup.
If you aren’t familiar with the BootRun service, this service will make all of the customizations after the sysprep work is complete during the deployment. You usually never see it because it runs on the first boot, makes the changes, and then removes itself from the machine.
In this case, the files are removed but the service entry is still there, hence the error that it can’t start up. VMWare has confirmed this to be a problem and they are investigating.
This customer runs the latest and greatest version of ESX and VirtualCenter so it appears that the bug hasn’t been fixed yet.